The problemSome case fans like the Nexus 120mm Real Silent case fan have "closed" corners. Most case fans have two flanges with a hole on each corner. With the "closed" corner fans each hole is connected by a tube to the corresponding hole on the opposite flange. I don't know if you can still understand me, so maybe some pictures will make it more clear.
The orange fan has "closed" corners. The black fan has the more standard corners.

The Dremel SolutionI put an already used brown cutting disk in my Dremel. Use the thickest cutting disk you have. Don't forget to put your goggles on. Little pieces of orange plastic will be flying everywhere. My Dremel has a variable speed from 10.000RPM to 33.000RPM. I set the speed switch to the second "click". You shouldn't use too high speeds, 'cause then the plastic will melt.
First cut two groves through the tube parallel and flush with the flanges. Then cut the rest of the tube into "fingers" that are a little wider than the thickness of the cutting disk. Next cut right through the middle of each "finger". The last bits of plastic are removed by gently tilting the cutting disk a little. (N.B. Never tilt the cutting disk when working with harder materials! The disk could splinter and parts of it could lodge themself into vital parts of your anatomy.)
Use your fingers to remove all (almost) loose pieces of plasic. Then smooth out the surface of the remaining plastic ridge by running the cutting disk over it.

The result:

The Hand Tool SolutionFirst use a hacksaw to saw two groves through the tube parallel and flush with the flanges.
Then take some pliers. Use them to squeeze hard on the tube. It will break into pieces.
Lastly use a small file to smooth out the edges.

ConclusionUsing hand tools, it takes me less than half the time to open a corner, compared to using a rotary tool. Not to mention that with the Dremel you end up with pieces of orange plastic in your hair and all over the room.

If anybody has other ideas (Blow torch? Chainsaw?) how to open the corners, feel free to add them.

Don't take the text in this post to serious. I was bored this afternoon. But now we have pretty pictures to point too, when people ask about the "closed" corner problem.

Edit: Added 120mm to the title, as I saw several people on the forum think other sizes had closed corners too.

I've wanted to do this for a number of different reasons, but I've always been a bit worried it might somehow affect the noise characteristics... maybe detract from the rigidity of the frame, or perhaps even the gripping/cutting might bend something very slightly out of shape, cause slight damage to the bearing etc...

I'm know I'm probably being a paranoid old woman (and the fans aren't exactly expensive) but can you confirm there are no adverse effects?

Very Nice , I like it. One minor suggestion I would have is to list the name/model number of the specific cutting tool that you used with the Dremel. It may be helpful for others in the future when they try and figure out which cutting disk to use.

One minor suggestion I would have is to list the name/model number of the specific cutting tool that you used with the Dremel.

I think the accessory I used is #540 1-1/4" Cut-Off Wheel screwed on a #402 Mandrel. I'm not sure about the disk, as it was one out of a box with assorted accessories. The #540 is the only one on the website with exact the same color, but in my box of pieces, I have disks of different thickness that are identical otherwise

I've wanted to do this for a number of different reasons, but I've always been a bit worried it might somehow affect the noise characteristics... maybe detract from the rigidity of the frame, or perhaps even the gripping/cutting might bend something very slightly out of shape, cause slight damage to the bearing etc...

I'm know I'm probably being a paranoid old woman (and the fans aren't exactly expensive) but can you confirm there are no adverse effects?

The rigidity of the frame hasn't changed. Look at the pictures above and compare the corner of the black fan to a cut corner of the orange fan. You'll see that the remaining ridge in the orange fan is still bigger than the small ridge on the black fan. I didn't expect other adverse effects either. Just make sure you handle the fan by the frame and don't use the hub to grip the fan.

But last night (01:00 AM) I tested if really nothing bad had happenend. I took my Morex Cubid 2677R case to the walk-in closet in my bedroom; removed the alarm clock from the bedroom; closed the airvent in the bedroom window; put the PSU brick under a stack of laundry; plugged the fans into the fanheaders on the VIA Epia 5000 motherboard and testing.......

I couldn't hear any difference between the Nexus fan I molested for the pictures above and an unmodified one.

I decided to try this method even though I do not own a xp 120 yet It was also an excuse to use the dremel. Like Tibors 1st post I used a cutting disk to flush out the tube with the end of the fans frame, but instead of cutting fingers in the tube frame I used a drum sander bit to cut the tube out. Also my computer seems to be running much quieter now then again it could be the fact I have not yet taken out my earplugs.

Thanks for this guide, it has helped me tremendously!
I'm not a DIY person so this was the first time I picked up a saw since school, and I probably won't be using a saw ever again which is a relief. Oh the horror!

LOL WIL! Great that you had the guts to mod that fan! I am a diy person but still was a bit scared going at my Nexus fan with a hacksaw, and huge pliers.. Worked a treat though, thanks for the clear guide mr T!

From chopping away at a Nexus fan with some tin snips, I found out half accidently, that if you cut out completely one side of the outer fan rim so that the fan blade is uncovered on that side, the fan still works, and a huge
breeze can be directed at hard to get to spots on the motherboard
by mounting that side strategically. I pointed it so the cut off side of the fan is cooling the ram, the chipset, and helping to cool the cpu, while the main part of the fan is blowing directly on the video card.

When using the saw-and-crush technique, you really only need to crush the tubes on the two "thick" corners. For the two "thin" corners, you can just grip the tube firmly and then bend it down, using a motion similar to snapping a twig. This will snap off the tube cleanly and leave clearance all around the fan hole. Just make sure the cuts at the ends of the tube go all the way through the tube before trying to snap off the tube.

For the two "thick" corners (that have no visible tube), I made a cut through the middle of the tube, parallel to the two cuts at the ends of the tube. This makes it easier to crush, since more pressure could be applied on a smaller portion of the tube. You'll have to crush twice, but you won't need the strength of He-Man. This really helps, especially when you have to crush the corners for eleven fans , like I did...

Hmmm, I just did the hacksaw, cornering crushing technique on my fan. I was very careful not to put pressure on the bearings when doing this....but...well....it now makes a loud humming noise... Oh well, time for a new fan, and my dremel...

Tibors, thanks for the excellent post and pics. Looking at your closeups of the Nexxus fan and the fact it already has "starter" holes, it looks like a nice fat drill bit, and your Dremel on high speed would cut right through in about 10 seconds. Am I wrong?

Who is online

Users browsing this forum: No registered users and 2 guests

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum